This invention relates to an improved hidden drain outlet structure for sink and particularly a hidden drain outlet structure that may be disassembled easily for cleaning and repairs, and is capable of discharging water smoothly without clogging the drain pipe.
The conventional drain outlet structure of a sink (as shown in FIG. 1) mostly has a control bar for lifting a plunger up or down when in use. The control bar sticks out from the drain pipe for a significant distance. The plunger head will be moved up above the basin bottom when draining water. It is easy to suck in foreign articles or garbage and block the drain pipe. The construction is rough and lacks aesthetic appealing. In view of these disadvantages, there are some refinements and improvements been developed. U.S. Pat. No. 5,509,150 (shown in FIG. 2) is one of the examples. It has a hidden drain feature which includes a drain pipe 10 connects with an outlet of the sink 1. In the drain pipe 10, there is a movable plunger 11 controlled by a pull rod 12 for moving up to drain water or moving down to retain water. At the top end of the pipe 10, a stationary disk 13 is provided for trapping foreign articles and garbage. Although it has a more appealing look than the conventional drain features, it has some disadvantages. For instance, the stationary disk 13 is fixed and cannot be removed. If the drain pipe 10 is clogged, the whole set of the drain pipe 10 has to be disassembled from under for doing the repairs job. It is very inconvenient and time consuming. Furthermore, as water discharge always forms a vortex at the outlet, the substantially flat top of the stationary disk 13 significantly slows down water discharge speed. Its fixed stationary disk 13 design also cannot match with most filtering articles now available in the market place that are designed for conventional sinks and drain features. There is still room for improvement.
It is therefore an object of this invention to provide an improved hidden drain outlet structure for sinks that has a drain head screwed to the upper end of a drain pipe. The drain head may engage with a filter which is easy to disassemble for repairs and maintenance. It is also capable of discharging water smoothly without clogging the drain pipe.